The Immunogenetics group of the Department of Genetics at the University Medical Center Groningen focuses on the development of organoid and organ-on-chip models of the human gut and liver. We are creating these stem cell-based models to study the role of human genetics and environmental factors (the exposome) in health and disease.
Organ-on-chip to study human gastrointestinal health and disease. At left, the logo of the Immunogenetics group, Department of Genetics, UMCG. We study the effect of genetics (circular DNA strand) and of environmental factors (e.g. diet, medication and lifestyle factors) on human tissues modeled on chip (our logo is based on the cover of Nature Biomedical Engineering, April 2020; current version has been resubmitted to Trends in Genetics). At right, the intestine-on-chip and liver-on-chip platforms that might be coupled in the near future.
Intestine-on-chip
As part of the NWO Gravitation program Netherlands Organ-on-Chip Initiative (NOCI), we are setting up models for the human small intestine (PIs: Dr. Iris Jonkers & Dr. Sebo Withoff, see https://umcgresearch.org/w/genetics and https://groningenmicrobiome.org).
Focus is on celiac disease, also known as gluten intolerance, an enteropathy of the small intestine driven by contributions from the patient’s genetic background and the exposome (microbiota as a triggering or driving factor, gluten as a driver). To study this, PhD researcher Renée Moerkens has applied the Emulate intestine-chip and modified the culturing conditions so that the cell type frequencies found on chip are similar to those found in the small intestine (as determined by single-cell RNAseq, unpublished results). Renée is now working on characterizing the system at single-cell level and studying the effects of celiac disease associated factors on intestinal barrier function.
The intestine-on-chip platform. (A) The Emulate chip consists of two channels (red and blue) separated by a permeable membrane and flanked by vacuum chambers (gray). Under microfluidic flow, epithelial barrier cells self-organize into villus-like folds (B) and the entire upper channel is covered with cells (C). We can now show that the major small intestinal cell types are recapitulated on chip (D), with FACS results indicating that cell frequencies on chip are similar to those found in small intestinal biopsies (E). An epithelial barrier is formed and closed ~8 days after seeding and is maintained for more than a week (F).
With the help of a grant from United European Gastroenterology (UEG), PhD researcher Joram Mooiweer was able to create organoid and organ-on-chip systems that combine intestinal epithelial cells and donor-derived intraepithelial lymphocytes (the cells that kill epithelial cells in celiac disease) from both patients and controls. In the coming year, his model will be used to test an antibody in human clinical trials for treatment of celiac disease complications.
Co-cultures of ASC-derived epithelial cells and autologous lymphocytes. In organoid medium, the effector cells do not survive, hence the organoids thrive (no fluorescence). In co-culture medium, the lymphocytes survive and start killing the organoids (fluorescence intensity increases). Upon addition of disease-associated cytokines, enhanced killing is observed.
In the next 5 years, the organ-on-chip platform will be made more complex by introducing other cell types involved in mucosal immunology of the intestine (endothelial cells, macrophages) and the microbiome based on the pilot work of Dr. Kieu Le and Dr. Jelle Slager. For this work PhD researchers Sajid Anwar, Hanna Simpson and Eline Smits have recently been hired. All this work has been and will be performed in the context of the NOCI program and the collaborating groups in the Netherlands (https://noci-organ-on-chip.nl).
To facilitate microbiome work at the UMCG, the UMCG is building a top-of-the-line lab where microbiota can be isolated from stool samples, specific microbiota can be isolated (culturomics) and microbiota can be introduced onto chip under anaerobic conditions (lab will be ready April 1, 2023). This work is being done in collaboration with the UMCG Microbiome Hub (https://groningenmicrobiome.org).
Liver-on-chip
The groups of Prof. Jingyuan Fu and of Dr. Sebo Withoff and Dr. Iris Jonkers (https://umcgresearch.org/w/genetics) are also developing a liver-on-chip platform. The first liver-chip project involves setting up a NASH-on-chip model and is being carried out by PhD researchers Victoria Palasantzas, Renée Moerkens and technical specialist Gwen Ruitenbeek (PIs: Prof. Jingyuan Fu, Prof. Hans Jonker). In a second project, PhD researcher Isabel Tamargo aims to study the roles of the liver, intestine and microbiome in drug metabolism (ERC project ‘BugDrug’ granted to Prof. Jingyuan Fu). To date, a protocol for differentiation of iPSCs into induced hepatocytes (hiHeps) has been realized and we are considering introducing Kupffer cells, stellate cells and endothelial cells in the context of both projects.
Characterization of iPSC-derived hepatocytes on-chip and in multi-well systems. (A) Although the current differentiation protocol leads to generation of both CK18-positive hepatocytes and CK7-positive cholangiocytes in the same culture, the human induced hepatocytes (hiHeps) express the hepatocyte-specific transcription factor HNF4 (middle panel) and albumin (A-lower panel and (B)). Hepatocytes produce (C) bile acids and (D) VLDLs. (E) Comparison of the transcriptomes of hiHeps-on-chip with hiHeps in wells and with liver biopsies shows that the hiHeps-on-chip express primary hepatocyte transcripts.
Part of the BugDrug project will also be carried out in the UMCG Microbiome Hub, where new hire Angela del Castillo Izquierdo will introduce microbiota into the chip system.